/// Based on your description the first suspect cause would be too high air pressure on the rear and too low on the front.

There are belt separations that will cause uneven wear but to have the defect occur in pairs, front and rear different but same side to side wheels is highly improbable.

Unless there is feathering in the wear on the front the most likely cause is air pressure.

It is possible to have two problems on the front, bab ball joints which would cause inside edge wear and out of alignment to cause the outside edge wear. Again possible but close inspection for feathering or cupping in the wear area will confirm or eliminate those solutions.

If a ball joint is that bad you should be able to shake the tire top to bottom while the car is on a lift. In early stages of wear the joint must be unloaded to test. For Volvo this means coil spring compressors on the front coil. The tie rod ends are checked by squeezing with a very large pair of pliers. If the bolt and cup can be forced together to reveal wear the tie rod end is bad. Small movements are allowable.

Eric,

You did not indicate the mileage on your '88. Mine had 150k when I bought it last fall. The tires had peculiar wear patterns, edge wear, cupping, scuffing, etc. I found missing sway bar bushings, bad ball joints and when I took the front end apart the control arm stay bushings were almost completely disintegrated. For about $80 in parts from Foreign Car Parts in Groton CT. I replaced ball joints, tie rod ends, all sway bar bushings and the control arm stay bushings(cone shaped rubber). It took about 5 hours on my '87 sedan but on the '88 wagon I could not get off one of the ball joints. I had to completely remove the control arm put it in a bench vise and beat on the stud with a large hammer before it came apart. So the wagon took about 7 hours. There are excellent instructions and tips in the 700/900 FAQ on the Brickboard. If you take it apart this far, it might be worthwhile to replace the struts as well. If you have the work done at a shop, the add'l labor to change the struts should be minimal. I believe the recommended tire pressure for the wagon is 30 psi front and 36 psi rear. It can be found on the label on the edge of the passenger side front door.

Your rear tyre wear IS from wrong pressures, TOO HIGH to be specific.... i run 29 PSI in my rear tyres here in Australia, mine wear COMPLETELY flat on the rear, even with slighty spirited driving.....I have Yokohama S306 tyres, (previous owners choice, i am putting on MX4+ or something next!), chances are your front tyres are wearing severly on the outside edges because of incorrect pressures, more specifically, TOO LOW. If you do any hard turns in your volvo, look at the way the tyres roll under on the front, quite badly, yes, ESPECIALLY when you are full lock. i run 32 psi in my front tyres, and avoid FAST HEAVY turns as much as possible, but i still go hard around some corners, and they REALLY chew the edge of the tyres (roads in aus are great...sure....). Otherwise they wear flat.

As with regards to the 5 speed....i am sure some exist.....I have a TRUE 5 speed sedan here in Australia, but manual 740's here are as rare as bat s*$t. I haven't even HEARD of a manual wagon here!

See ya,

Azza

Eric: if by "true 5-speed" you mean "4-on-the-floor" plus the 5th gear overdrive button, my late departed '85 245* (non-turbo)diesel station wagon was so equipped; but I much prefer its '86 740 GLE TurboDiesel straight-6 auto. trans. replacement, much better for the 40-to-50% city driving that I do, and more responsive at freeway on-ramps than "old Betsy" was, even with a 2-to-4 second turbo 'lag'; with a chance to keep moving at the on-ramps, instead of having to stop before entering, the very effective kickdown more than makes up for any perceived advantage of 5 gears and a clutch! 215,000 miles and still hummin! *(U.S.A.)